Variable speed transmission device



July 23, 1935. N, J. OAK 2,008,992

VARIABLE SPEED TRANSMISSION DEVICE Filed Dec 25, 1932 2 Sheets-Sheet l INVEN TOR.

July 23, 1935. N. J. OAK 2,008,992

VAR IABLE SPEED TRANSMISSION DEVICE Filed Dec. 25, 1952 2 Sheets-Sheet 2 INVENTOR.

, Patented July 23, 1935 UNITED. STATES ,PATENT OFFICE v 2,008,992 I VARIABLE srsnn mansmssron nsvrcr:

Noah Johnson Oak, Lynn, Mass. Application December 23, 1932, Serial No. 648,715 4 Claims. (01. 14-23011) This invention relates to power transmission of the external contacting circurnierence 7 at their the variable speed type, it has for its purpose to intermeshing point, said belt connectingwith provide a new and efilcient means for varying the and riding upon a second driven or driving sheave speed of a driving and a driven unit; to provide a whichmay optionally be oi. the variable type or new and novel combination of an expanding of the fixed construction. v 5 sheave and V-belt transmission; to provide new Referring to the accompanying drawings which and novel variable speed transmission means in form a part of this specification and in which combination with a belt, all adaptable to vary similar letters of reference'refer to similar parts the revolutions per minute of the driven unit; throughout the various views.

10 to provide variable transmission means capable Figure 1 is a side view of the sheave mounted l) of greater speed than has heretofore been possion a motor A and on the sliding base B with the ble on variable transmission types; to provide a speed adjustment screw R holding the sheave at variable transmission'mean s' of lighter construcits low speed position. The intermeshing side tion than has heretofore been deemed feasible; to sections C and C are shown distanced upon the provide a variable transmission adaptable to sleeve E, with the belt D in low speed position. 12;,

- mechanism of smaller horsepower and to larger Figure 2 is a side view of the sheaves mounted horsepower than has heretofore been possible; side by side on the shaft F for a multi-belt unit, to render feasible the use of multiple driving belts with the intermeshing side sections C and C disof small size for transmitting large horsepower; tanced upon the shaft F, with the belt D in low to thereby reduce installation and operating speed position. 2

costs; to ailforda greater efliciency of variable Figure 3 is a side view of the sheave mounted transmission means; to provide a constant drivon the motor A and on the sliding base B with ing force efliciently developed from a variable the speed adjustment screw R set at high speed transmission;' to provide an improved construcposition. The intermeshing side sections C and tion providing for the changing of the sheave unit C are shown close together on the sleeve E, in 25 end' for end on the shaft so as to insure the pull which position they are forced by action caused of the belt in the right direction; to provide two by the keys J and J in the spiral keyways G and intermeshing sections conically shaped on one G N and-N show set screws in opposite ends side, designed to interlock at their contacting of the sleeve E to provide for turning the unit sides so as to function as a sheave, said interend for end on the motor spindle S, so the motor 30 meshing conical sections adaptable for adjust- A'will always pull the load on the belt D in the ment closely. together or distanced so as to vary right direction on the sheaves and the keys J and the external circumference at their contacting J registering in the spiral keyway G and G points, and to' function with a connecting V belt which have left and right hand leads and form a that will lay in or fit onto the sides of the V V on the sleeve E. U is the sliding plate under 35 formed by the two intermeshi'ng conical sections the motor A, and is a part of base 13. at their intermeshing point, so as to form a driv- Figure 4 shows an end view of the sheave ing or a driven unit; to provide a means of movmounted on the motor A. The plate U may be ing the two intermeshing conical faced sections adjusted by the adjustment screw'R on the bot- 40 inwardly or outwardly uniformly in order to hold tom frame T of the base B. The two intermesh- 40 the alignment of the belt; to provide an autoingside sections C and C are shown close tomatic means of maintaining the proper tension gether and the belt D shown at high speed posion the belt in relation to the load pulled; to protion. The sleeve E is fastened to motor spindle vide a means for adjusting the relative position S by the set screws N and N". The two keys J 5 of the sheave parts as required for varying speeds; and J 2 are located in parts C and C. The tension 5 to provide a variable speed transmission which, spring H extends through the sheave and is faswhen not in motion, allows the belt used thereon tened by pins I and I to parts C and C. to become slack; to. thereby lengthen the normal Figure 5 shows a sectional view of the sheave life of the belt, decrease belt stretching, reduce on lines A-A in Figure 6 with thetwo intermesh- 5 upkeep costs; and to provide the various other ing side sections C and C distanced with the advantagesvand results made evident from the belt D at low speed position. The sleeve E is following specification. shown mounted on the motor spindle S, the two I accomplish the object of my invention by the intermeshing side sections C and C being shown use of an adjustable sheave or sheaves for a mounted on and keyed to the sleeve E by the driving or driven unit, on which rides a belt upon keys J and J in the 1m and right hand spiral 55 koyways G and G in the sleeve E. N and N show the two set screws by means of which the sleeve .can be'fastened to the motor spindles from either end of the sheave. spring which acts as a governor and holds the- H shows the tension intermeshing sidesecti'ons together when the unit is running idle.. The spring Hextends through the parts '0 and C and is fastened by pins I and I.

Figure 6 is an end view of Figure or the sheave. Figure-7 shows a detail of keys J and J which keys are assembled from .the inside of the inter-1 sections 0 and C intermeshed closely together to hold belt D in its highest speed position.

Figure 9 shows a sectional view of an alternate means of accomplishing the same resultsas shown 'in Figure 5, by threading the sleeve 'E' with a left and right thread X and X and threading the keys in parts '0 and C'- to fit the thread X and x=. Figure 10' shows a sectional .view of a construction accomplishing the same results as shown in Figure 5 piusa reversing meansythls being accomplished by two sets of spiral keyways G, G,

G? and G cut left and right and opposite hand, so that the keys J 'and-J in parts C and C can register and travel fronrone set to the other setof said keyways so to insure the belt D always pulling into the V formed by the parts C'and C as regulated by the keyways. The compression spring 0 is held on sleeve j E by part 0 and washer'E. The washer E isheld to the side section C by the screws K which slide in a clearance provided through said side section C. t

Figure 11 shows a sectional view of an alternate construction accomplishing the same results as shown. in Figure 5, the intermeshing side sections C and C" being' mounted on the sleeve-E and held at varying speed positions by action of the mechanical governor balls N and N and N and N as they revolve, the parts C and C having av straight keyway which registers with and fits the key onthe sleeve E the governor balls being pinned to cam Q on the sleeve E 7 Figure 12 shows a sectional view of an alternate means of accomplishing the same results as shown in Figure 5, by facing the hubs of the intermeshing side'sections C and C with the left and right hand spiral cam parts Y and Y, and mounting side sections C and C on the sleeve E on which sleeve are mounted the other parts of the spiral cams Z and Z which register and contact with the parts Y-and Y on the side sections. N and N show set screws which secure the sleeve E to the motor spindle S.

While I have illustrated and described a preferred construction for carrying my invention into effect, this is capable of variations or modifications without departing from the spirit of the invention. I therefore do not wish to be limited to the exact details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

My variable speed sheave is designed for use with any standard sheave or pulley with which it is combined by a constant length V belt and means of changing the center to center distance between the sheaves for the purpose of changing the speed of the driven sheave.

It will be understood by those conversant with the art to which this invention appertains, that when connected as above, the variable sheave,

cause said side sections to move inwardly'toward each other, and the intermeshing circumference is by such inward movement, increased in diameter until all belt slack is taken up, and the belt tension is rendered sufllcient to pull the load imposed upon it.

It will be further understood that while I have herein described means upon a sleeve for chang- -ing the relative position of the sheave sections,

the-position of said means may as well be upon the shaft of the driving unit, and I desire to have. the appended claims construed in the light that one is an equivalent of the-other.

Thebelt will not slip on my variable speed sheave because the greater the pull on the beltthe, greater the tendency of the intermeshing side sections to come together by action of' the keys lnthe said spiral keyways, and as said side sections come together, the greater becomes their intermeshed circumference, and said'circumference continues to increase, until'the'belt tension is sufficient to carry the load.

The belt holds the proper alignment as the two intermeshing side "sections move equally inwardly or outwardly due to action of the keys in the left and right handspiral keyways which vform an equal sided V.

The governor spring H is provided to hold the intermeshing side sections together when idle,

' or when'in motion but pulling no load.

My variable speed-sheave is assembled on-the motor spindle with the belt pulling in the direction toward the point of the V formed by spiral keyways.

It will be also understood that where-I-have herein described my construction as applicable to driving units, it is as well applicable to driven units and wi11.be so regarded in the .construction of the claims and'elsewhere'.

Having thus described my invention, I claim as new and desire to secure by Letters Patent of the United States of America:'--

1. In a variable speed. pulley with faces that are identical, that is adaptable to'be mounted and keyed to a rotatable shaft from. either' face according to the driving direction ofthe pulley, the pulley consisting of two segmentally intermeshing cone sections, meshed on their conical sides, a sleeve having a spiral keyway that starts from each endandconverges. equally towards its center, upon which said cone sections are mounted and keyed, keys in the hub of the cone sections to have flattened faces that fit snugly into the spiral keyways on the sleeve, and are assembled from the end of the sleeve, a spring through the cone sections and fastened to their outer faces, which tends to hold the pulley together as a unit so when in motion the conical faces of the cone sections will be contacting the belt with a light pressure, so that the belt will get traction sufllcient only to make the keys in the spiral keyways pick up and carry the load imposed on sleeve having two spiral keyways that start from each end near the same point and converge equally toward the center but in difierent directions, upon which said cone sections are mounted and keyed, the keys in the hub of the cone sections to have flattened faces that fit snugly into the spiral keyways on the sleeve and are assembled from the ends of the sleeve, 9. spring through the cone sections and fastened to their outer faces, which tends to hold the pulley together as a unit so when it is in motion the conical faces of the cone sections will be contacting the belt with a light pressure, so there will be traction on the belt sufficient only to make the keys in the spiral keyways pick up and carry the load imposed on the pulley by the belt.

3. A variable speed unit comprising a non speed varying type grooved pulley, a v-belt, an adjustable sliding motor base for varying the size of the belt contacting surface of the variable pulley, and a variable pulley as set forth in claim 1.

4. A variable speed unit comprising a non speed varying type grooved pulley, a V-belt, a variable pulley as set forth in claim 1, and a means of varying the distance between the driving and driven pulleys.

NOAH J. OAK. 

